Two-cycle gas engine



April 9, 1935. F. HAGENMULLER Er AL TWO-CYCLE GAS ENGINE Filed June24,11952 2 Sheets-Sheet 1 April 9, 1935.

F. HAGENMLLER ET AL TWO-CYCLE GAS ENGINE Filed June 24, 1932 2sheets-sheet 2 Patented Apr. 9, vl9i5 Lacasse Y TWO-CYCLE GAS ENGINEFriedrich Hagenmiiller and Ludwig Prechtei, Nu-

remberg, Germany,assigno1a to Maschin Vfabrik Augsburg-Numberg A. G.,Nuremberg,`

, aeorporation of Germany Appunti@ .nme 24. 1932, semi Nn. 619,010

In Germany December 28, 1931 Our invention relates to a two-cycle gasengine capable of attaining high outputs atvhigh speeds. Highpowe'r gasengines-i. e. gas engines of several thousand H. P heretofore known runs slowly, are very large and heavy and are accordingly very expensive topurchase and-to erect. It is well known that engines of higherY speedshave smaller dimensions, and attempts have,Ik

diiliculties'are overcome .by the present invention providing for notonly the exhaust but also all air admission (including scavenging air)being 20 governed by ports and working piston only.

Thus, the problem of the forces of acceleration of the piston movestothe center of the cylinder,

for air valves is disposed of.- As far as the gas is concerned, thedifficulty of keeping the gas valve, through which at high outputs aconsiderlimits as regards Vsize and weight, is overcome by the admissionof the gas as'quickly as possible after closure ofthe exhaust ports, sothat, on the one whand, the time available for forcing in the gas isample to enable the use cfa small gasvalve, and, on theother hand, thegas pressure remains comparatively low so that a light compressor issufficient. Furthermore, suil'lcient time remains for a thorough mixingof the gas and air Vin the working cylinder before ignition.

It isalso important that the gas valve be provided with a positivevalvegear. Only with such a device can thenecessary DI'eGisionA beobtained as regards the moment of the opening and closing foregoing isimportant for the operationy of the engine, and only with 'sucha devicecan the engine run atv high Thus, automatic inlet valves for the gas, orvalvesfwhose opening is dependent upon the pressure inthe cylinder andwhich have no external positively driven members are of no use.

On the annexed drawings, on which are shown, 50 designed in accordancewith the present invention, T

Fig. l shows a double acting two-cycle gas engine, the essential partsof which are shown in section, the other parts being shown inelevation.

,at I3 and I 4 respectively).

able quantity of gas has to now, within admissible of the gas valvewhich as will be seenfrom the Y by way of illustration, embodiments ofan engine Y Figs'. 2 and' 3 show a two-stroke gas engine, certain partsbeing omitted. i y According to Fig. l, the cylinder Ihas in the centerfour superposedp'orts 2, 3,-4 and l. The ports 3 and 4 areprovided forthe admission o f- .lg

thescavenging air, whichl is supplied to said.

ports by an electricallydriven blower 6 through th'e pipe 'I in which acollector 8 is tted. f

Ports 2 and 5 are exhaust ports leading to the open through pipes 9 andIl in which collector 10 vessels III and I2 are iltted.

Each cylinder end has a gas inlet valve (shown The piston Il inside thecylinder drives the crankshaft I9 in the direction of the arrow2Ilfthrough pistonrrod I6 15 connecting rod I1 and crank I 8. Thedirection of'turning is shown by arrow 20.

The lower. end of the Vpiston I i controls the ports 2 and 3,- whiletheupper end controls the ports land 5. `The ports 2 and 3, and l and l 420respectively are opened when the controlling end A wheel 2| vmounted onlthe crankshaft I9 drivesthe equal-sized wheel 23 by means of the 30transmission4 22 so that the camdisc .24 securedlto wheel 2 3 rotates atexactly the same .speed as the shaft I9. Contacting with the edge o fthis cam disc at two diametrically opposite points are '35 rollers 25and 26 each of which is carried by a lever system.' Thelever system forthe upper gas valve I3 consistsof the,v levers 21 and 23 and rod28,*while that for the lower gas valve il consists of bell-cranklever3I. I'he ends of levers 23.40 and 3l Vbears against spring-actuatedstems 30 and 32 of the gas valves I3 and,

.As thev cam disc 2 4 rotates in the direction of the arrow, cam 33first lifts the upper roller 26V thus opening the gas valve* I3 forabrief time.k 45- After a revolution of 180 the cam reaches roller 25 andopens gas` valve Iljwhich immediately closes again after. the cam haspassed.

The compressor 34 draws gas through the pipe 50 E 35 and forcesitthrough piping 36 and the two branchesv3l and 38 to the valves I3 andI4 through which at the moment they .open the gas enters the cylinder.In the piping 3,6 is a collector 39 for compensating any sudden uctua-55 OFFICE i j t tions in the iiow of gas through piping il, 31 and 38.

Now, the operation of the engine will be described as regards the upperend of the cylinder. When the piston occupies its lowermostgpositionscavenging air enters the cylinder I through port 4 driving the burnedgas out of the cylinder through exhaust port 5.

Now, when the piston moves upwards, its upper end first closes thescavenging air port 4, and then the exhaust port 5. As shown in Fig. 1of the drawings, which alsoshows the corresponding position of theconnecting rod I1, the crank I8, and the cam disc 24. 'I'he cam 3lcarried by the disc 24 acting through the roller 2i and the lever system21, 29, 28, 30, on the gas valve I3 the latter commences to open, andgas enters the cylinder. The gas admission is completed, when the upperend of the piston has about reached the position shown by-the upperdash-andedot line. Then follows the compression the charge, and, shortlybefore the upper dead point of the piston, ignition and explosion,resulting in the descent of lthe piston. As soon as the upper end of thepiston reaches the dotted line position 42 the burned gas" hows-throughport 5 into the exhaust pipe I0. Then, at the dash line position 4 I,scavenging port 4 is opened, scavenging air enters the cylinder anddrives'out the rest of the gas.. Then the cycle is repeated.

The design just describeddiifers from all previous designs of gasengines, apart fromy othercharacteristics, particularly in the admissionof the gas immediately the cylinder is entirely closed. With previousdesigns `the gas admission has taken place either while the exhaust wasstill open so that gas could escape with the exhaust, or so late thatthe compression period was almost at an end and high pressure alreadyexisted in the cylinder so that the gas also had to be put under highpressure before admission was possi-v ble.

As to the lower end of the cylinder the operation is the same as the onejust described and it is therefore not necessary to describe it sepa.-V

rately. Y

The two-stroke gas engine according to Fig. 2 is also designed inaccordance with the present invention but in addition has a device foradmitting air, after the closing of the exhaust ports, into the `upperhalf of the cylinder when the piston moves upwards and into the lowerhalf of the cylinder when the piston moves downwards.

This device consists of a port 44 for the upper and a port 45 for thelower half of the'cylinder. Each port is controlled by a rotary slidevalve- 4I for port 44 and" for port 4l. Instead of ro,-Y tary slidevalves ordinary valves can of course are driven by the crankshaft I9 inthe usual way (not shown) so that at the proper time air from the piping44 enters the cylinder. This can take placeeither simultaneously withthe admission of gas' through either gas valve I3 or I4, or before, or,if the ports are provided nearerthe ends of the cylinder, afterwards.The purpose of this introduction of lcompressed air is well known andtherefore, does not require explaining here.

The two diagrams show single-cylinder engines.

Lacasse The same design can, of course, be applied to multi-cylinderengines, several cylinders being arranged side by side and transmittingtheir power on to the same crankshaft in the usual way. `In this case,of course, only one scavenging air blower and one gas compressor arerequired for all the cylinders.

The principle of this invention canbe applied without alteration to asingle acting engine, as well as to the double acting engineillustrated. It would not appear to be necessary, however, to make aseparate description of this.

Y Engines constructed in accordance with this invention may, withoutdeviating from the principle of the invention, also include devices orsystems already known in engine construction and which also in this casecan be of advantage. For instance, as shown in Figure 3, rotary slidevalves 49 andV 5l can be fitted into the exhaust pipings l and III,close to the ports 2 andi. These valves close the exhaust ports as soonas the piston has closed the respective scavenging Port, so that gas'canbe admitted without waiting for the piston to close the exhaust ports.

We claim: s Y

-1. A highspeed high combustion engine comprising a cylinder having anintake port, an exhaust port anda port for the supply of scavenging air,a piston reciprocal within said cylinder, the exhaust port and thescavenging air supply port beingv disposed to be successively'uncoveredby the outer end portion of the piston during inward movement of thepiston and immediately prior to the piston reachs ing its limit ofVinward movement within the cylinder, the scavenging air supplyportbeing disposed entirely inwardly of the means for supplyingscavenging air under constant high pressure through said scavenging airport and in greater volume than the piston displacement during the timethat said scavenging air port is uncovered, the intake port beinglocated in the cylinder head; a normally closed valve controlling saidintake port, means for opening said valve immediately after the'pistonduring its outward movement has closed the exhaust and scavengingl airports, means for forcing explosive gas into'the cylinder through saidintake port during outward movement of the piston and prior to theoutward movement of the piston resulting in an appreciable pressurebeing generated within the cylinder, and means whereby said intake valveis closed prior to the piston reaching its limit ofy outward movement.

2. An internal combustion engine as set forth in claim 1 including valvemeans operable to.

close the exhaust port when during outward movement ofthe piston andprior to closing of the exhaust` portby the' piston the same, has closedthe scavenging air pori-.

3'. An internal combustion engine as set forth in claim 1 includingmeans for the introduction of air into the' cylinder between thecylinder head and the exhaust port during outward movement of the pistonand following closing of the scavenging air port and the exhaust port bythe piston.Y

FRIEDRICH HAGENMILER.. LUDWIG PRECHTEL.

exhaust port,

